I am and have been at the scorer’s table for every home game over the last 10 years. It would be a challenge at our school to add another person for each game. Yes, we have people capable of the task, but it doesn’t always fit in to other people’s schedules. Sometimes we scramble to find a fill-in when someone is sick.
Beyond that, let’s leave the shot clock to college and pro. For a lot of teams, there is still quite a bit of learning going on even during a game.